Re: [PATCH V2 0/3] fstests: fixes for 64k pages and dax

Jeff Moyer
2020-02-21T20:11:20Z

Hi, Darrick,

"Darrick J. Wong" <darrick.wong@oracle.com> writes:

>> One class of failures is tests that create a really small file system
>> size. Some of those tests seem to require the very small size, but
>> others seem like they could live with a slightly bigger size that
>> would then fit the log (the typical failure is a mkfs failure due to
>> not enough blocks for the log). For the former case, I'm tempted to
>> send patches to _notrun those tests, and for the latter, I'd like to
>> bump the file system sizes up. 300MB seems to be large enough to
>> accommodate the log. Would folks be opposed to those approaches?
>
> Seems fine to me. Do we have a helper function to compute (or maybe
> just format) the minimum supported filesystem size for the given
> MKFS_OPTIONS?

Not that I could find. I'm not sure how you'd do that, even.

>> Another class of failure is tests that either hard-code a block size
>> to trigger a specific error case, or that test a multitude of block
>> sizes. I'd like to send a patch to _notrun those tests if there is
>> a user-specified block size. That will require parsing the MKFS_OPTIONS
>> based on the fs type, of course. Is that something that seems
>> reasonable?
>
> I think it's fine to _notrun a test that requires a specific blocksize
> when when that blocksize is not supported by the system under test.

OK.

> The ones that cycle through a range of block sizes, not so much--I guess
> the question here is can we distinguish "test only this blocksize" vs
> "default to this block size"? And do we want to?

Well, I'd like to prevent false test failures. In this instance, the
block size is required in order for the system to function. I'm
guessing this is a new and special kind of suck. If we treat the
MKFS_OPTIONS as advisory, then there will be false positive failures.
If we treat MKFS_OPTIONS as mandatory, then there will be less test
coverage for a given set of options. I think that's the preferrable
solution, but I'm probably too focused on this one use case.

-Jeff